Question 1 (50 marks) a) The impact mill machine has been used for size reduction process. The crushed granite has been characterized using screen analysis. Table 1 shows the cumulative mass distribution of the crushed granite particles at different impact velocities of 50 and 70 m's. The sphericity and specific gravity of the particles are 0.67 and 2.7, respectively. Table 1: Screen analysis of crushed granite particle Particle Cumulative weight (%) size (mm) 50 m/s 70 m/s 50.30 2.15 3.11 50.60 4.98 8.37 S 1.18 9.53 16.21 $2.36 17.16 27.19 s 4.75 32.97 49.94 S 9.50 78.32 94.57 $ 13.20 100.00 100.00 i) Calculate the arithmetic mean diameter of the particles at impact velocity of 50 m/s. (10 marks) ii) Calculate the volume-surface mean diameter for both impacts and provide a comment (10 marks) iii) Estimate the percentage of the particles smaller than 8 mm for 50m's impact velocity (10 marks) b) 2 ton/h of the feed granite in (a) having an average diameter of 2.0 cm with impact machine of 50 m/s was discharged as a product as shown in Table 1. i) If the power required to crush the 2 ton/h of granite is 1.0 kW. What would be the power consumption if the feed capacity is increased to 10 ton/h. Use Rittinger's law. (10 marks) ii) Estimate the power required to produce the crushed granite using Bond's Law. (10 marks)